Typebar guide and repulser device

ABSTRACT

A typebar guide and repulser device is disclosed comprising a cantilevered leaf spring and two spaced guide dogs having opposing surfaces mounted adjacent the cantilevered leaf spring. Means are also disclosed for converging the two opposing guide dog surfaces towards one another upon depression of the cantilevered leaf spring.

D United States Patent 1 [111 3,734,262

Doll et al. 1 1 May 22, 1973 54 TYPEBAR GUIDE AND REPULSER 1,064,674 6/1913 Ursbruck ..197/43 DEVICE 1,969,411 8/1934 Miller ..197 43 3,19 ,427 6 1965 P d ..197 43 X [751 Invemms Dryden; s 642 374 21972 Aim??? ..197i4s x Cappotto, Syracuse; Herrick R. Diamond; Ernest F. Lohr, both of FOREIGN PATENTS 0R APPLICATIONS Homer an of 33,46! 12/1904 Switzerland ..197/43 [73] Assignee: SCM Corporation, New York, NY. 573,913 4/1933 Gen'nany ..197/43 [22] Filed: May 1971 Primary Examiner-Edgar S. Burr [21] Appl. N0.: 140,419 Attorney-Robert B. Kennedy 52 us. c1 ..197/43 [571 ABSTRACT [5 Int. Cl. A typebar guide and epuiser device is disclosed comof Search prising a cantilevered leaf spring and two spaced guide dogs having opposing surfaces mounted adjacent the References Cmd cantilevered leaf spring. Means are also disclosed for UNITED STATES PATENTS converging the two opposing guide dog surfaces towards one another upon depress1on of the cantil- 441,654 12/1890 Foss et a1 ..197/43 X evered leaf spring. 550,990 12/1895 Merritt 900,931 10/1908 Jackson ..197/43 X 8 Claims, 11 Drawing Figures Patented May 22, 1973 3 Sheets-Sheet 1 INVENTOR. PETER A. DOLL SAMUEL D. CAPPOTTO HERRICK R.DIAMOND ERNEST F. LOHR Patented May 22, 1973 3,734,262

3 Sheets-Sheet 2 INVENTOR.

PETER A. DOLL SAMUEL D- CAPPOTTO HERR CK R. DIAMOND ERNEST F. LOHR Patented May 22, 1973 3,734,262

3 Sheets-Sheet I3 INVENTOR. PETER A. DOL L SAMUEL D. CAPPOTTO BY HERRICK R.D|AMOND ERNEST E OHR TYPEBAR GUIDE AND REPULSER DEVICE BACKGROUND OF THE INVENTION This invention relates generally to typewriters, and particularly to means for guiding typebars as they approach a typewriter platen for printing, and for repulsing typebars away from the platen after the printing operation has been performed.

Heretofor, the prevalent means employed for guiding individual typebars from their stayed position to their print position within a printing station at the platen has comprised a segmented base plate into which the typebars are pivotally mounted at their base. Two spaced type guides having confronting arcuate surfaces are also mounted adjacent the typewriter platen and printing station -for final alignment just prior to typebar impact with the platen. In operation, an individual typebar pivots at its base and is guided by the sides of the slot into which it fits in the segmented base plate. As it approaches the platen it also passes between incident lips of the two spaced type guides. If properly centered the typebar clears the confronting arcuate guide surfaces and strikes the platen or paper thereon; but if slightly off-center the typebar strikes one of the arcuate guide surfaces and is deflected towards the center of the flight path. The terminal portion of the flight paths of the upper portion of each typebar adjacent the type head which portion passes between the two spaced guides adjacent the platen are substantially coincident. The flight paths of the remaining, lower portion of the typebars are diverse as also are those of the upper portions during their initial approach to the guides from their stayed positions.

Use of the just described fixed typebar guides adjacent the platen has given rise to several technical problems which have in turn led to an impairment of the quality of the machine print in the form of lack of character clarity, non-uniformity of print impact, and low lateral tolerance in character location on the surface of the imprintable medium. For example, typebars which are properly aligned pass through the guides without striking their arcuate surfaces and thus strike the platen or paper thereon with greater force than do those which are slightly misaligned and strike one or more of the arcuate surfaces of the rigid guides adjacent the platen. The spacing between the guides must also be substantial, such as to leave one or two mils clearance with the typebar, in order to prevent pronounced typebar deceleration and vibration from occuring as a misaligned typebar first strikes one guide surface, rebounds to another, and so forth. This excess spacing is productive of lateral imprecision in print location and, in severe cases, of even a blurring of print as the character font on the typehead strikes the paper at an angle to the platen normal. In addition, the passive guide means of the prior art have not driven typebars back towards their stayed position after their print operation has been effected at the platen. Consequently, the typebars have lingered somehwhat in contact with the platen which contact interval has lessened the degree of sharpness of the printed characters. Moreover, the typebars themselves have had to be prehardened to withstand the severe wear produced by continuous striking of the rigid guides over prolonged periods of time. Such prehardening has, of course, produced added costs.

Accordingly, it is a general object of the present invention to provide an improved typebar guide and repulser device.

More specifically, it is an object of the present invention to provide means for guiding typebars as they approach a typewriter platen which action does not significantly impair print quality.

Another object of the invention is to provide typebar guide means which upon print operation drives the guided typebars away from the typewriter platen towards their stayed positions thereby reducing the time interval during which the type is in printing contact with the typewirter platen or imprintable medium thereon.

Another object of the invention is to provide means for guiding typebars into a print station without inducing significant vibrations in the typebars.

Yet another object of the invention is to provide typebar guide means with which un-prehardened typebars may be used over long periods of time.

SUMMARY OF THE INVENTION Briefly described, the present invention is a typebar guide and repulser device comprising a cantilevered leaf spring and two spaced guide dogs having opposing surfaces mounted adjacent the cantilevered leaf spring. Means are provided for converging the two opposing guide dog surfaces towards one another upon depression of the cantilevered leaf spring.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a typebar guide and repulser device incorporating principles of the present invention.

FIG. 2A is a side view in elevation of the device shown in FIG. 1 positioned with a typebar encountering the device as it approaches a typewriter platen.

FIG. 2B is a plan view of the device shown in FIG. 1 as positioned in FIG. 2A.

FIG. 3A is a side view in elevation of the device shown in FIG. 1 with a typebar positioned for printing with font on the typehead in contact with the typewriter platen.

FIG. 3B is a plan view of the device shown in FIG. 1 as positioned in FIG. 3A.

FIG. 4 is a perspective view of another embodiment of a typebar guide and repulser device incorporating principles of the present invention.

FIG. 5A is a side view in elevation of the device shown in FIG. 4 positioned with a typebar encountering the device as it approaches a typewriter platen.

FIG. SB is a plan view of the device shown in FIG. 4 as positioned in FIG. 5A.

FIG. 6A is a side view in elevation of the device shown in FIG. 4 with a typebar positioned for printing with font on the typehead in contact with the typewriter platen.

FIG. 6B is a plan view of the device shown in FIG. 4 as positioned in FIG. 6A.

FIG. 7 is a perspective view of another embodiment of a typebar guide and repulser device incorporating principles of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in more detail to the drawing there is shown in FIG. 1 a typebar guide and repulser device incorporating principles of the present invention. The device is mounted to frame adjacent platen 12 to guide and repulse typebars such as typebar 14 as they approach the platen individually for printing. The device here is seen to comprise a cantilevered leaf spring 15 mounted at its lower end to frame 10 by screws 16. The leaf spring projects upwardly through slot 18 in frame 10 with its upper end disposed in spaced, substantially parallel relation with platen 12 to transverse typebar flight path 20. From the upper end of the cantilevered leaf spring horizontally projects two parallel yokes 22 to which are rotatably held two guide dogs 24 by pivot pins 26. One end of each guide dog 24 is located between two opposed, limiting surfaces of a bifurcated retainer 28 rigidly mounted atop frame 10.

In operation, as typebar 14 approaches from its stayed position platen 12 along typebar guide path it passes between guide dogs 24 and contacts cantilevered leaf spring 15 thereby assuming the position depicted in FIGS. 2A and 2B. As the typebar thereafter continues its movement towards the platen it depresses cantilevered leaf spring 15 and causes the upper end of the leaf spring to move towards the platen. As guide dogs 24 are mounted to the upper end of the leaf spring one end thereof will be forced against limiting surface 33 of bifurcated retainers 28 which retainers are rigidly mounted to frame 10. This action will cause guide dogs 24 to rotate and thus cause the opposite ends thereof to converge towards one another laterally into typebar guide path 20. The guide dogs are so sized and located as to be spaced apart a distance approximating the width of the typebars when the guide dogs are oriented coplanarly as shown in FIGS. 3A and 3B. Thus, should a typebar be slightly off-center flight path 20 as it passes between the guide dogs it is centered by the converging guide dog closer thereto. When font 32 on typehead 30, which head is mounted atop typebar 14, strikes platen 12 or paper thereon the components of the guiding and repulsing device, the typebar, and the platen assume the relative positions shown in FIGS. 3A and 33. After contact the depressed cantilevered leaf spring drives the typebar back from the platen towards its stayed position.

In FIG. 4 another embodiment of the present invention is shown. Here again a cantilevered leaf spring 35 is seen to be fastened at its lower end to frame 36 by screws 37. The leaf spring, which may or may not be laminated, extends upwardly through slot 38 in frame 36 to transverse a typebar flight path. To the top of frame 36 are rotatably mounted two guide dogs 40 by pivot pins 41. The opposing surfaces of the two spaced guide dogs are indented to define two opposing guide dog indentations 42 into which are disposed tabs 44 of cantilevered leaf spring 35.

In operation, as typebar 45 having typehead 46 secured to the top thereof approaches platen 48 it passes between rotatably mounted guide dogs 40 and strikes cantilevered leaf spring 35 to occupy the position shown in FIGS. 5A and 5B. As it continues its travel towards the platen it depresses leaf spring 35 forcing tabs 44 attached thereto to move against a limiting surface of guide dog indentations 42. This action causes the guide dogs to rotate. The contour of the peripheral surface of guide dogs 40 is irregular. As a result rotation of the guide dogs causes their opposing surfaces to converge. Should typebar 45 be off-center the typebar flight path the guide dog closer thereto will move against it in cam-like action to laterally center it. When the font on typehead 46 strikes platen 48 or paper thereon the components of the guiding and repulsing device, the typebar, and the platen assume the relative positions shown in FIGS. 6A and 63. After contact the depressed cantilevered leaf spring drives typebar 45 back from the platen to its stayed position.

FIG. 7 shows yet another embodiment of the invention comprising a cantilevered leaf spring 50 secured at its lower end to frame 52 by screws 53. The leaf spring extends upwardly through slot 56 in frame 52 to transverse a typebar flight path as in the previously described embodiments. A conventional fixed typebar guide is rigidly mounted to the top of frame 52 having two spaced, opposing, arcuate surfaces 58 and two coplanar limiting surfaces 59. Two upwardly projecting tabs 60 of cantilevered leaf spring 50 contact limiting surfaces 59. Two ends 63 of a generally U-shaped resilient wire 65 are sandwiched between cantilevered leaf spring 50 and arcuate surfaces 58. A lower portion of wire 65 is confined in slot 66 in the leaf spring by frame 52. With this configuration wire ends 63 are made to function as guide dogs in that depression of cantilevered leaf spring 50 forces ends 63 to laterally converge towards one another as they move against the two spaced, opposing, arcuate surfaces 58. Once the cantilevered leaf spring is relaxed after it repulses a typebar away from the platen the lateral resiliance of wire 65 causes ends 63 to diverge along arcuate surfaces 58.

It should be understood that the just-described embodiments are merely illustrative of principles of the invention and that many modifications may be made thereto without departure from the spirit and scope of the invention as set forth in the concluding claims.

What is claimed is:

l. A typebar guide and repulser device comprising: two spaced guide dogs having opposing surfaces; means supporting said spaced guide dogs for movement from an ineffective position in which said opposed surfaces are at a predetermined distance from each other to a converged position having said opposing surfaces spaced a distance less than said predetermined distance from each other for guiding and positioning a typebar; and

a cantilevered leaf spring engaging each of said two spaced guide dogs in a positive two direction driving relationship, said cantilevered leaf spring moving said spaced guide dogs in one direction from said ineffective position to said converged position upon depression of said cantilevered leaf spring and returning said spaced guide dogs in a second direction to said ineffective position upon release of said cantilevered leaf spring.

2. A typebar guide and repulser device in accordance with claim 1 wherein said supporting means includes means pivotably mounting each of said two spaced guide dogs to said cantilevered leaf spring.

3. A typebar guide and repulser device in accordance with claim 2 wherein said supporting means includes bifurcated guide dog retention means, and wherein a portion of said pivotably mounted guide dogs is disposed within said bifurcated retention means.

4. A typebar guide and repulser device in accordance with claim 1 wherein said two spaced guide dogs are pivotally mounted adjacent said cantilevered leaf spring.

5. A typebar guide and repulser device in accordance with claim 4 wherein each of said two spaced guide dog opposing surfaces are indented to define two opposing guide dog surface indentations.

6. A device for guiding and repulsing a typebar traveling within a typebar flight path towards a typewriter platen for printing, said device comprising:

two spaced guide dogs having opposing surfaces;

means supporting said spaced guide dogs for moving said opposing surfaces from an ineffective position outside said typebar flight path to a converged position within said typebar flight path; and

a cantilevered leaf spring engaging each of said two spaced guide dogs in a positive two direction driving relationship and positioned in said typebar flight path for movement in a first direction by a traveling typebar to move said opposing surfaces to said converged position and thereby guiding the traveling typebar to the platen, said cantilevered leaf spring operable when moving in a second drection for returning said opposing surfaces to said ineffective position and repulsing the typebar away from the platen after printing.

7. A device for guiding and repulsing a typebar in accordance with claim 6 wherein said spaced guide dogs are each indented to define two opposing guide dog indentations, and wherein a portion of said cantilevered leaf spring is disposed within said two opposing guide dog indentations.

8. A typebar guide and repulser device comprising: two resilient spaced guide dogs being biased in a direction away from each other and being biased toward an ineffective position;

means guiding said spaced guide dogs from said ineffective position where said spaced guide dogs are at a predetermined distance from each other to a converged position where said spaced guide dogs are spaced a distance less than said predetermined distance from each other for guiding and positioning a typebar; and

a cantilevered leaf spring for moving said spaced guide dogs in one direction from said ineffective position to said converged position upon depression of said cantilevered spring and for allowing said spaced guide dogs to move in a second direction from said converged position to said ineffective position upon release of said cantilevered leaf spring. 

1. A typebar guide and repulser device comprising: two spaced guide dogs having opposing surfaces; means supporting said spaced guide dogs for movement from an ineffective position in which said opposed surfaces are at a predetermined distance from each other to a converged position having said opposing surfaces spaced a distance less than said predetermined distance from each other for guiding and positioning a typebar; and a cantilevered leaf spring engaging each of said two spaced guide dogs in a positive two direction driving relationship, said cantilevered leaf spring moving said spaced guide dogs in one direction from said ineffective position to said converged position upon depression of said cantilevered leaf spring and returning said spaced guide dogs in a second direction to said ineffective position upon release of said cantilevered leaf spring.
 2. A typebar guide and repulser device in accordance with claim 1 wherein said supporting means includes means pivotably mounting each of said two spaced guide dogs to said cantilevered leaf spring.
 3. A typebar guide and repulser device in accordance with claim 2 wherein said supporting means includes bifurcated guide dog retention means, and wherein a portion of said pivotably mounted guide dogs is disposed within said bifurcated retention means.
 4. A typebar guide and repulser device in accordance with claim 1 wherein said two spaced guide dogs are pivotally mounted adjacent said cantilevered leaf spring.
 5. A typebar guide and repulser device in accordance with claim 4 wherein each of said two spaced guide dog opposing surfaces are indented to define two opposing guide dog surface indentations.
 6. A device for guiding and repulsing a typebar traveling within a typebar flight path towards a typewriter platen for printing, said device comprising: two spaced guide dogs having opposing surfaces; means supporting said spaced guide dogs for moving said opposing surfaces from an ineffective position outside said typebar flight path to a converged position within said typebar flight path; and a cantilevered leaf spring engaging each of said two spaced guide dogs in a positive two direction driving relationship and positioned in said typebar flight path for movement in a first direction by a traveling typebar to move said opposing surfaces to said converged position and thereby guiding the traveling typebar to the platen, said cantilevered leaf spring operable when moving in a second drection for returning said opposing surfaces to said ineffective position and repulsing the typebar away from the platen after printing.
 7. A device for guiding and repulsing a typebar in accordance with claim 6 wherein said spaced guide dogs are each indented to define two opposing guide dog indentations, and wherein a portion of said cantilevered leaf spring is disposed within said two opposing guide dog indentations.
 8. A typebar guide and repulser device comprising: two resilient spaced guide dogs being biased in a direction away from each other and being biased toward an ineffective position; means guiding said spaced guide dogs from said ineffective position where said spaced guide dogs arE at a predetermined distance from each other to a converged position where said spaced guide dogs are spaced a distance less than said predetermined distance from each other for guiding and positioning a typebar; and a cantilevered leaf spring for moving said spaced guide dogs in one direction from said ineffective position to said converged position upon depression of said cantilevered spring and for allowing said spaced guide dogs to move in a second direction from said converged position to said ineffective position upon release of said cantilevered leaf spring. 